This technology relates to a display apparatus and an electronic apparatus, and particularly to a display apparatus wherein a plurality of pixels each including an electro-optical element are disposed in rows and columns or in a matrix and an electronic apparatus which includes a display apparatus.
In recent years, in the field of display apparatus for displaying an image, a display apparatus of a planar type, that is, of a flat panel type in which a plurality of pixels or pixel circuits are disposed in a matrix has been popularized rapidly. As one of flat panel type display apparatus, a display apparatus is available which uses, as a light emitting element of a pixel, an electro-optical element of the current driven type which emits light of the luminance which varies in response to the value of current flowing therethrough. As the current driven type electro-optical element, an organic EL element is known which makes use of a phenomenon that, if an electric field is applied to an organic thin film of an organic material, then it emits light utilizing electroluminescence (EL) of the organic material.
An organic EL displaying element which uses an organic EL element as a light emitting element of pixels has such a characteristic as described below. In particular, since the organic EL element can be driven with an application voltage of 10 V or less, the power consumption can be suppressed low. Further, since the organic EL element is a self-luminous element, visibility of a displayed image is high in comparison with a liquid crystal display apparatus. Besides, since an illuminating member such as a backlight is not required, reduction in weight and thickness can be achieved readily. Furthermore, since the speed of response of the organic EL element is approximately several μ seconds and is very high, an afterimage upon moving picture display does not appear.
The organic EL display apparatus can adopt any of a simple or passive matrix method and an active matrix method as a driving method similarly to the liquid crystal display apparatus. However, although the passive matrix type display apparatus is simple in structure, since the light emission period of the electro-optical element is reduced by increase of the number of scanning lines, or in other words, by increase of the number of pixels, there is a problem in that it is difficult to implement a large-sized and high-definition display apparatus.
Therefore, in recent years, development of an active matrix type display apparatus in which current to flow to an electro-optical element is controlled by an active element such as, for example, by an insulated gate type electric field effect transistor provided in a pixel in which the electro-optical element is provided has been and is proceeding energetically. As the insulated gate type electric field effect transistor, a TFT (Thin Film Transistor) is used popularly. Since, in the active matrix type display apparatus, the electro-optical element continues light emission over a period of one display frame, it can be implemented readily in a large size and high definition.
A pixel circuit including a current-driven type electro-optical element which is driven by the active matrix method includes, in addition to the electro-optical element, a driving circuit for driving the electro-optical element. One of such driving circuits is disclosed, for example, in Japanese Patent Laid-Open No. 2009-103868 (hereinafter referred to as Patent Document 1). The driving circuit of Patent Document 1 is incorporated in a pixel circuit and is configured from a driving transistor 22 for driving a current-driven type electro-optical element such as, for example, an organic EL element 21, a writing transistor 23 and a retaining capacitor 24.
In Patent Document 1, an organic EL display apparatus 10B in which peripheral circuit sections (40, 50 and 60) are mounted on a display panel 70 in which a pixel array section 30 configured from a great number of unit pixels 20b is incorporated is disclosed (refer to paragraph 0027, FIGS. 1, 10 and so forth of Patent Document 1).
Further, in Patent Document 1, it is described to commonly use one power supplying line 32 (32−1 to 32−m) for four subpixels 20W, 20R, 20G and 20B which belong to two vertically neighboring rows which configure the same unit pixel 20b. Furthermore, in Patent Document 1, it is described that, since the circuit scale of the writing scanning circuit 40 can be reduced by commonly using one power supplying line 32, reduction of the width of the molding of the framework of the display panel 70 can be achieved (refer to paragraph 0136 of Patent Document 1). Here, the “molding of the framework” is that region of the display panel 70 around a pixel array section 30 which does not contribute to image display.